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CN-118908703-B - Preparation method of solid spherical alumina granulated powder

CN118908703BCN 118908703 BCN118908703 BCN 118908703BCN-118908703-B

Abstract

The invention discloses a preparation method of solid spherical alumina granulated powder, which comprises the steps of firstly adding a specific anionic surface active dispersing agent to disperse and mix alumina powder and a sintering aid, then adding a specific cationic surface active dispersing agent to neutralize the surface charge of the anionic surface active dispersing agent to obtain alumina slurry, and finally spraying and granulating to obtain the solid spherical alumina granulated powder.

Inventors

  • YU QIWEI
  • HUANG QIFAN
  • YANG SHUBIAO
  • QIU YUHONG
  • ZHANG CAISHENG

Assignees

  • 厦门海赛米克新材料科技有限公司

Dates

Publication Date
20260512
Application Date
20240716

Claims (9)

  1. 1. A preparation method of solid spherical alumina granulated powder is characterized by comprising the following steps: Step 1, firstly, putting 50-60 wt% of alumina powder, 3-6 wt% of sintering aid, 0.2-0.6 wt% of anionic surface active dispersant and 35-45 wt% of deionized water into a ball mill according to the proportion, and performing ball milling and dispersing to obtain alumina slurry A; Step 2, adding a binder and a plasticizer into the alumina slurry A according to the proportion, and performing ball milling and mixing to obtain an alumina slurry B; wherein the addition amount of the binder is 1.0-3.0% of the mass amount of the relative alumina powder, and the addition amount of the plasticizer is 0.5-3.0% of the mass amount of the relative alumina powder; Step 3, adding a cationic surface active dispersing agent into the alumina slurry B according to the proportion, and performing ball milling dispersion again to obtain an alumina slurry C, wherein the addition amount of the cationic surface active dispersing agent is 0.05% -0.15% of the mass consumption of the alumina powder; Step 4, finally, carrying out spray granulation on the alumina slurry C, wherein the spray granulation is carried out under the conditions that the air inlet temperature is 250-280 ℃, the air outlet temperature is 100-110 ℃, and the tower internal pressure is-10-50 Pa, so as to obtain the solid spherical alumina granulation powder; in the step1, the molecular structure of the anionic surface active dispersant is shown as a formula I: In the formula I, R 1 、R 2 is one or more of H、COOH、COO - Na + 、COO - K + 、COO - NH + 4 、COO - N + H(CH3) 2 CH 2 CH 2 OH、COO - N + H(CH 2 CH 3 ) 3 , R 3 is one of butyl, isobutyl, isooctyl and isobornyl, R 4 is one of H and methyl, a=0.1-0.4, b=0.16-0.67, c=0.23-0.44 and n=3-14, wherein the values of a, b and c are the molar ratio of the corresponding monomers; in the step 3, the molecular structure of the cationic surface active dispersant is shown as II: In the formula II, R 1 、R 2 and R 5 are respectively one of H and methyl, R 3 is one of butyl, isobutyl, isooctyl and isobornyl, R 4 is one of H and methyl, R 6 is And CH 3 COOCH 2 CH(OH)CH 2 -; a=0.1 to 0.4, b=0.16 to 0.67, c=0.23 to 0.44, n=3 to 14, wherein the values of a, b and c are the molar ratio of the corresponding monomers.
  2. 2. The method for preparing solid spherical alumina granulated powder according to claim 1, wherein in step 1, the particle size of the alumina powder is 2.0-3.0 μm, and the sintering aid comprises 15-45 wt% of SiO 2 、15wt％～23wt％CaCO 3 and 33-70 wt% of talcum powder.
  3. 3. The method for preparing solid spherical alumina granulated powder according to claim 1, wherein in step 1, the rotation speed of the ball mill is 20-35 rpm, and the ball milling time is 12-24 h.
  4. 4. The method of claim 1, wherein in step 2, the binder is one of polyvinyl alcohol and aqueous acrylic resin, and the plasticizer is one or both of polyethylene glycol and glycerin.
  5. 5. The preparation method of the solid spherical alumina granulated powder according to claim 1 is characterized in that in the step 2, the rotation speed of ball milling is 20-35 rpm, the time of ball milling is 2-6 h, and in the step 3, the rotation speed of ball milling is 20-35 rpm, and the time of ball milling is 1-5 h.
  6. 6. The preparation method of the solid spherical alumina granulated powder is characterized by comprising the steps of firstly adding 5-30 parts of maleic anhydride or acrylic acid monomer, 23-64 parts of polyethylene glycol monoether acrylate, 20-60 parts of (methyl) acrylic acid ester monomer, 0.5-5 parts of initiator and 60-140 parts of solvent into a container in sequence, stirring uniformly at normal temperature to obtain a uniform mixed solution, then adding 30-60 parts of mixed solution into a four-mouth flask, continuously introducing nitrogen, heating to 75-95 ℃, preserving heat for 20-90 min, then dripping the rest mixed solution in 0.5-4 h, preserving heat for 1-3 h, adding 30-100 parts of deionized water, reducing the temperature to below 40 ℃, adding 5-40 parts of neutralizing agent, carrying out neutralization reaction for 0.5-1 h, and then removing the solvent by reduced pressure distillation to obtain the anionic surface active dispersing agent.
  7. 7. The method for preparing solid spherical alumina granulated powder according to claim 6, wherein the (meth) acrylic acid ester monomer is one of butyl (meth) acrylate, isobutyl (meth) acrylate, isooctyl (meth) acrylate, isobornyl (meth) acrylate, the initiator is one of azobisisobutyronitrile and ammonium persulfate, the solvent is one or more of ethyl acetate, isopropanol, water, toluene, propylene glycol methyl ether and butyl acetate, and the neutralizing agent is one of sodium hydroxide, potassium hydroxide, N-dimethylethanolamine, triethylamine, ammonia water and ammonium hydroxide.
  8. 8. The preparation method of the solid spherical alumina granulated powder is characterized in that in the step 3, 5-40 parts of cationic monomer, 23-64 parts of polyethylene glycol monoether acrylate, 20-60 parts of (methyl) acrylic ester monomer, 0.5-5 parts of initiator and 60-140 parts of solvent are added into a container, uniform mixed solution is obtained through stirring at normal temperature, 30-60 parts of mixed solution is added into a four-neck flask, nitrogen is continuously introduced, the temperature is raised to 75-95 ℃, the temperature is kept for 20-90 min, then the rest of mixed solution is completely dripped within 0.5-4 h, the temperature is kept for 1-3 h, then the temperature is lowered to 60 ℃, then 5-40 parts of chloride is added, the temperature is kept for 0.5-2 h, then 20-50 parts of deionized water is lowered to 40 ℃ and finally 5-40 parts of fatty acid are added, the solvent is removed through reduced pressure distillation after the reaction for 0.5-1 h, and the cationic surface active dispersing agent is obtained.
  9. 9. The method for preparing solid spherical alumina granulated powder according to claim 8, wherein the cationic monomer is one of dimethylaminoethyl (meth) acrylate, N-dimethylacrylamide and acrylamide, the (meth) acrylic acid ester monomer is one of butyl (meth) acrylate, isobutyl (meth) acrylate, isooctyl (meth) acrylate and isobornyl (meth) acrylate, the initiator is one of azobisisobutyronitrile and ammonium persulfate, the solvent is one or more of ethyl acetate, isopropanol, water, toluene, propylene glycol methyl ether and butyl acetate, the chloride is one of methyl chloroacetate, epichlorohydrin and chloroacetic acid, and the fatty acid is one of acetic acid, lauric acid and stearic acid.

Description

Preparation method of solid spherical alumina granulated powder Technical Field The invention relates to the technical field of ceramic materials, in particular to a preparation method of solid spherical alumina granulated powder. Background The alumina ceramic has the characteristics of high strength, good corrosion resistance, excellent insulativity and the like, and is widely applied to the fields of new energy automobiles, LEDs, semiconductors and the like. The dry pressing forming process has the advantages of high production efficiency, high automation degree, low production cost and the like, and is one of the main processes for manufacturing the alumina ceramic parts. Because alumina powder is a ridged raw material, has the problems of small loose density, poor fluidity and the like, and cannot be directly used for a dry-pressing molding process, the alumina powder needs to be prepared into slurry before dry-pressing molding, and then the alumina slurry is dried by a spray granulation method to form alumina granulation powder with good fluidity. The shapes of the alumina granulated powder are generally three types, namely solid sphere, apple shape and hollow sphere, wherein the solid sphere alumina granulated powder has the best fluidity and the largest apparent density, and the completely solid sphere alumina granulated powder is difficult to manufacture in actual production and manufacture. Chinese patent CN104150883B discloses a preparation method of alumina granulated powder, and proposes to use a method of combining centrifugal force and pressure to produce solid granulated powder, however, the method has the problems of complex structure of production equipment, difficult production control, and hollow spheres with a certain proportion of products. Therefore, the method for preparing the completely solid spheroidized alumina granulated powder is simple to control, and is an urgent problem to be solved in the whole industry. Disclosure of Invention The invention aims to provide a preparation method of solid spherical alumina granulated powder, which realizes complete solid spheroidization of the alumina granulated powder by adjusting the dispersibility of alumina slurry, has simple requirements on manufacturing equipment and low control difficulty. In order to achieve the above object, the solution of the present invention is: The preparation method of the solid spherical alumina granulated powder comprises the following steps: Step 1, firstly, putting 50-60 wt% of alumina powder, 3-6 wt% of sintering aid, 0.2-0.6 wt% of anionic surface active dispersant and 35-45 wt% of deionized water into a ball mill according to the proportion, and performing ball milling and dispersing to obtain alumina slurry A; Step 2, adding a binder and a plasticizer into the alumina slurry A according to the proportion, and performing ball milling and mixing to obtain an alumina slurry B; wherein the addition amount of the binder is 1.0-3.0% of the mass amount of the relative alumina powder, and the addition amount of the plasticizer is 0.5-3.0% of the mass amount of the relative alumina powder; Step 3, adding a cationic surface active dispersing agent into the alumina slurry B according to the proportion, and performing ball milling dispersion again to obtain an alumina slurry C, wherein the addition amount of the cationic surface active dispersing agent is 0.05% -0.15% of the mass consumption of the alumina powder; Step 4, finally, carrying out spray granulation on the alumina slurry C, wherein the spray granulation is carried out under the conditions that the air inlet temperature is 250-280 ℃, the air outlet temperature is 100-110 ℃, and the tower internal pressure is-10-50 Pa, so as to obtain the solid spherical alumina granulation powder; in the step1, the molecular structure of the anionic surface active dispersant is shown as a formula I: In the formula I, R 1、R2 is one or more of H、COOH、COO-Na+、COO-K+、COO-NH+4、COO-N+H(CH3)2CH2CH2OH、COO-N+H(CH2CH3)3, R 3 is one of butyl, isobutyl, isooctyl and isobornyl, R 4 is one of H and methyl, a=0.1-0.4, b=0.16-0.67, c=0.23-0.44 and n=3-14, wherein the values of a, b and c are the molar ratio of the corresponding monomers; in the step 3, the molecular structure of the cationic surface active dispersant is shown as II: In the formula II, R 1、R2 and R 5 are respectively one of H and methyl, R 3 is one of butyl, isobutyl, isooctyl and isobornyl, and R 4 is one of H and methyl; r 6 is And CH 3COOCH2CH(OH)CH2 -; a=0.1 to 0.4, b=0.16 to 0.67, c=0.23 to 0.44, n=3 to 14, wherein the values of a, b and c are the molar ratio of the corresponding monomers. In the step 1, the particle size of the alumina powder is 2.0-3.0 mu m, and the sintering aid comprises 15-45 wt% of SiO 2、15wt％～23wt％CaCO3 and 33-70 wt% of talcum powder. In the step 1, the rotating speed of the ball mill is 20-35 rpm, and the ball milling time is 12-24 h. In the step 2, the binder is one of polyvinyl alcohol and